In the current network auction system, products are auctioned via a network. In the network auction, when a product has been purchased, the product goes to the winning bidder, and then the seller and bidder evaluate each other's actions. Generally, the earlier the product is dispatched, the more satisfied the bidder is, that is, the higher evaluation the seller tends to receive. For example, PLT 1 discloses an auction evaluation support system to evaluate the dispatch of a product to the seller.